Animal systemic insecticide

ABSTRACT

An animal systemic insecticide having the formula ##STR1##

FIELD OF THE INVENTION

This invention relates toO,O-dimethyl-2,2,2-trichloro-1-hydroxy-1(pyranyl-2-oxy)ethylphosphonateand its use as an animal systemic insecticide.

BACKGROUND OF THE INVENTION

An insecticide is a compound that controls insect life. Insect life maybe controlled by killing a substantial proportion of an insectpopulation. Compounds which control insect life in this manner must behighly toxic to the insect population and non-toxic to other livingthings.

Insecticides may be applied to an area where it is desired to controlinsect life by a variety of methods. These methods include topicalapplication and systemic application.

Topical application is application of the insecticide directly to thearea where the insect desired to be controlled is present or may light.Insecticides applied topically remain localized near the site ofapplication.

By contrast, systemic insecticides are applied to a site remote from thearea where the insect to be controlled is present or may light. Asystemic insecticide is capable of freely translocating within a livingbody. The insecticide translocates within the living body from the siteof application to the area where the insect to be controlled is present.The insect is killed in the area where it is present. The living bodythrough which the insecticide has translocated remains unharmed.

Whatever the method of application, a certain minimum amount of acompound is effective to control insect life. This amount is the"insecticidally effective amount."

Insecticides are commonly used to control insects which are harmful toman. Insects may be harmful to man either directly, e.g. by carryingdisease, or indirectly, e.g., by destroying animal life, plant life,food products, or other commodities.

Blowflies are an example of an insect which destroys animal life.Screwworm flies are a type of blowfly which present a particularproblem.

Screwworms populate warm climates. They are found in the southern UnitedStates, including Texas, New Mexico and Arizona, and Central and SouthAmerica. These insects are dangerous to cattle, hogs, horses, mules,sheep, goats, dogs and other domestic and wild animals.

Screwworms attack a host animal, e.g., cow, hog, etc., at an open woundor other diseased body opening and lay their eggs at the site of theopening. Screwworm larvae feed on the wound or opening and invadehealthy tissue surrounding it. Infestation of an opening in this mannerprevents the opening from healing.

The odor of an infested opening attracts additional flies, includingother types of blowflies, to the opening. The newly attracted flies laytheir eggs near the infested opening. Successive generations of insectscause a serious inflammation. Unless the blowfly infested opening istreated effectively, death of the host animal is inevitable.

To date, treatment of openings attacked by screwworms has been limitedto application of a topical smear. Care must be taken to insure that theentire infested area has been completely covered by the smear. It isdifficult to protect inaccessible areas of the animal in this manner.

DESCRIPTION OF THE INVENTION

This invention relates toO,O-dimethyl-2,2,2-trichloro-1-hydroxyl-(pyranyl-2-oxy) ethylphosphonateand its use as an animal systemic insecticide. This compound has thestructure: ##STR2##

It has now been discovered that2,2,2-trichloro-1-hydroxy-1-(pyranyl-2-oxy) ethylphosphonate is usefulas an animal systemic insecticide for the control of blowflyinfestations. An insecticidally effective amount ofO,O-dimethyl-2,2,2-trichloro-1-hydroxy-1-(pyranyl-2-oxy)ethylphosphonate may be applied to an animal with a screwworm infestedwound at a site remote from the area of screwworm attack, e.g. byfeeding, and will kill the screwworms at the wound location.

PREPARATION

O,O-dimethyl-2,2,2-trichloro-1-hydroxy-1-(pyranyl-2-oxy)ethylphosphonate was prepared by the following procedure.

Ten (10) grams (g) of O,O-dimethyl-2,2,2-trichloro-1-hydroxyethylphosphonate having the structure: ##STR3## was dissolved in 50milliliters (ml) of benzene and 20 ml of dihydropyran. A drop ofconcentrated sulfuric acid was added and the mixture was warmed to 40°C. and maintained at that temperature for 1/2 hour.

The O,O-dimethyl-2,2,2-trichloro-1-hydroxy-1-(pyranyl-2-oxy)ethylphosphonate was washed with sodium bicarbonate, dried and stripped.n_(D) ³⁰ =1.4920. Structure was confirmed by infrared (IR) spectroscopy.

TESTING

O,O-dimethyl-2,2,2-trichloro-1-hydroxy-1-(pyranyl-2-oxy)ethylphosphonate was administered orally by stomach tube to mice. Aftertreatment, the animals were sacrificed and muscle tissue was taken forbioassay with blowfly larvae. The blowfly larvae were allowed to feed onthe muscle tissue excised from the treated mice. Systemic activity wasevaluated as a function of larval mortality after the larvae had fed onthe tissue.

The average percent larval mortality at 100, 200 and 400 milligrams ofO,O-dimethyl-2,2,2-trichloro-1-hydroxy-1-(pyranyl-2-oxy)ethylphosphonate per kilogram of mouse weight was 100%. The number ofmice treated at each dosage was two. TheO,O-dimethyl-2,2,2-trichloro-1-hydroxy-1-(pyranyl-2-oxy)ethylphosphonate did not kill any of the mice.

TEST RESULTS

O,O-dimethyl-2,2,2-trichloro-1-hydroxy-1-(pyranyl-2-oxy)ethylphosphonate was translocated through the bodies of the mice tomuscle tissue and was effective to kill blowfly larvae aftertranslocation. The compound was non-toxic to the mice.

FORMULATIONS

A formulation is the incorporation of an active ingredient in a formwhich may be administered directly to an animal. In this case, theactive ingredient isO,O-dimethyl-2,2,2-trichloro-1-hydroxy-1-(pyranyl-2-oxy)ethylphosphonate.

O,O-dimethyl-2,2,2-trichloro-1-hydroxy-1-(pyranyl-2-oxy)ethylphosphonate may be formulated by impregnation on an inert carrieror agent. The formulatedO,O-dimethyl-2,2,2-trichloro-1-hydroxy-1-(pyranyl-2-oxy)ethylphosphonate may then be incorporated on or in an animal's feedsupply for ingestion by the animal.

What is claimed is: 1.O,O-Dimethyl-2,2,2-trichloro-1-hydroxy-1-(pyranyl-2-oxy)ethylphosphonate.
 2. A method of killing insect larvae in an animalhaving an opening infested with said larvae comprising administering aninsecticidally effective amount ofO,O-dimethyl-2,2,2-trichloro-1-hydroxy-1-(pyranyl-2-oxy)ethylphosphonate to said animal.
 3. A method as defined in claim 2wherein said insects are blowflies.
 4. A method as defined in claim 3wherein said blowflies are screwworm flies.
 5. A method as defined inany of claims 2, 3, or 4 wherein saidO,O-dimethyl-2,2,2-trichloro-1-hydroxy-1-(pyranyl-2-oxy)ethylphosphonate is administered by feeding.
 6. A composition comprisingan insecticidally effective amount ofO,O-dimethyl-2,2,2-trichloro-1-hydroxy-1-(pyranyl-2-oxy)ethylphosphonate formulated with an inert diluent carrier or agent.